Conventionally, optical coordinate recognition apparatuses are known, such as a touch panel including a plurality of infrared light-emitting devices and a plurality of infrared light-receiving devices provided so as to be opposed to the respective infrared light-emitting devices.
In general, such an optical coordinate recognition apparatus detects whether a light path formed between a pair of light-emitting device and a light-receiving device is shielded or not, and calculates coordinates of a position at which the user has manipulated based on the detected result.
In this scheme, however, the resolution achieved will be as low as the light path formed between an LED and a PTR of each pair. It is thereby difficult to identify the precise manipulation position.
For the sake of improved precision, it is possible to obtain a higher resolution by increasing the number of light-emitting devices and light-receiving devices and narrowing the distance between the light paths such that the light paths are closer to one another. Due to restrictions in size of the light-emitting devices and the light-receiving devices, however, there is a limit to how narrow the distance between the light paths can be made.
Under the circumstances, it has been desired to develop a technique allowing an optical coordinate recognition apparatus to identify the manipulation position with high precision.